Color photographic elements and process



United States Patent 3,506,443 COLOR PHOTOGRAPHIC ELEMENTS AND PROCESS Robert F. Motter, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Nov. 18, 1965, Ser. No. 508,596

Int. Cl. G03c 1 14 US. Cl. 96-55 12 Claims ABSTRACT OF THE DISCLOSURE Silver halide emulsions, particularly those containing an incorporated color-forming coupler, are advantageously green-sensitized with a supersensitizing combination of (1) certain oxacarbocyanine dyes that have no more than one phenyl substituent and (2) certain benzimidazolocarbocyanine dyes and further sensitized by processing them in the presence of certain silver halide thioether sensitizers that are incorporated in the immediate green-sensitized emulsion layer, another layer in the photographic element containing the green-sensitized emulsion layer or incorporated in a color developing solution containing a p-phenylenediamine used to process the immediate emulsion, provided the thioether is present in the emulsion during color development. The immediate supersensitized emulsions containing the thioether sensitizer are especially advantageous when processed in a color developer solution containing a dialkylamino-p-phenylenedian1ine color developin g agent because of synergistic increases in green speed of up to about 336%.

This invention relates to photographic silver halide emulsions and, in particular, one aspect of this invention relates to an improved means for sensitizing photographic silver halide emulsions containing color-forming compounds or couplers.

It is well known to increase the sensitivity of photographic emulsions by addition thereto of certain nonmetallic compounds of Group VI A of the periodic table alone or in combination with salts of gold or other noble metals or with reducing agents, the aforementioned compounds are generally known as chemical sensitizers. Such chemical sensitizers are believed to react with the silver halide to form, on the silver halide, minute amounts of sensitivity specks which are capable of increasing the sensitivity of developing out emulsions by very large factors. The process of chemical sensitization, however, reaches a definite limit beyond which further addition of sensitizer, or of further digestion with the sensitizer present, merely increases the fog of the photographic emulsion with constant or decreasing speed.

More recently, it has been found that the speed of chemically sensitized emulsions could be further increased without a concomitant increase in fog, by the addition of certain thioether compounds to the chemically sensitized photographic emulsion. Since sensitization with compounds of this type does not require digestion, they have been assumed to promote development.

It is further known that certain sensitizing dyes or combinations thereof are particularly useful in photographic silver halide emulsions containing color-forming couplers. See, for example, Jones and Spence US. Patent 2,912,329 which describes improvements in the green sensitization of multi-layer color elements.

ice.

Furthermore, it is also known that the sensitization produced by a given dye varies somewhat with the type of emulsion in which the dye is incorporated or by varying the conditions in the emulsion. Thus, the sensitization may be increased by increasing the silver ion concentration or decreasing the hydrogen ion concentration (i.e., increasing the alkalinity), or both. Sensitization can also be increased by bathing supports coated with a spectrally sensitized emulsion in water or in aqueous solutions of ammonia. Such a process of altering the sensitivity of a sensitized emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen ion concentration is commonly called hypersensitization. Hypersensitized emulsions have generally exhibited poor keeping qualities.

It has been desired to improve the green sensitization of multilayer, incorporated-coupler elements as well as to obtain color products of higher over-all speed. Reference is made to Schwan and Jones US. application Ser. No. 404,888, filed Oct. 19, 1964, which describes the use of supersensitizing combinations comprising certain oxacarbocyanine dyes with certain benzimidazolocarbocyanine dyes in the green sensitive emulsion layer of various elements to provide improvements in stain, stability and speed therein.

The incorporated-coupler materials of the aforementioned application were, after exposure, given the E-2 process for Kodak Ektachrome film. This process, see for example, US. Patent 2,944,900, comprises:

(1) Negative development (2) Reversal flash exposure (3) Color development (4) Silver bleaching (5) Fixing The color developer utilized in the above process had the following compositions:

Water, to F. (21 to 27 C.)1.00 liter Benzyl alcohol-6.00 ml.

Sodium hexametaphosphate--2.00 grams Sodium sulfite, desiccated5.00 grams Trisodium phosphate-40.00 grams Potassium bromide'0.25 grams 0.1% solution of potassium iodide-10.00 ml.

Sodium hydroxide-6.00 grams 4-amino N ethyl-N-[fl-methane-sulfonamide-ethyl]m- -toluidine sesquisulfate rnonohydrate --1l.33 grams Ethylenediamine sulfate--7.80 grams Citrazinc acid (2,6 dihydroxyisonicotinic acid)1.50

grams 1 Color developing agents of the above type have also been utilized for color negative elements containing incorporated color-forming couplers.

While attempts to obtain higher speeds by the use of thioether-type sensitizers in conventionally-sensitized incorporated-coupler color negative elements processed in color developers containing sulfonamido-p-phenylenediamine developing agents have produced speed increases in the redand blue-sensitive layers, little or no increase in speed, and in some cases even a loss in speed, has been produced in the green-sensitive layers.

It is, therefore, an object of my invention to provide novel photographic silver halide emulsions containing incorporated color-forming coupler compounds.

Another object is to provide a novel multicolor, multilayer photographic element containing incorporated color-forming couplers.

Another object is to provide a novel multilayer, multicolor element process combination for increasing the speed of the green-sensitive emulsion layer as much or more than the speed of the red-sensitive emulsion layer and blue-sensitive emulsion layers of said element.

Another object is to provide a synergistic speed increase in the green-sensitive layer of my novel multilayer color-forming coupler incorporating element by using my color development process.

Still further objects will become evident from the following specification and claims.

These and other objects are accomplished by the practice of my invention which will now be described.

I have now found that when thioether-containing multilayer, multicolor elements that incorporate color-forming couplers are processed in color developers wherein a dialkyl-p-phenylenediamine developing agent is substituted for the sulfonamido derivative, speed increases are produced in all of the light-sensitive layers. 1 have also found that any loss in green speed obtained in thioether-containing elements containing known green sensitizing combinations processed in sulfonamido-pphenylenediamine color developers may be overcome by the use of a green-sensitive layer containing my preferred green supersensitizing combinations of oxacarbocyanine with benzimidazolocarbocyanine dyes.

I have further found that the use of the preferred green-sensitizers in conjunction with a thioether sensitizer in an incorporated-coupler color element processed in a dialkyl-p-phenylenediamine color developer appears to produce synergistic effects in that the speed obtained in this manner is significantly greater than the speeds obtained (1) when elements containing conventional green sensitizers plus a thioether sensitizer are processed in a dialkyl-p-phenylenediamine color developer, or (2) when elements containing the preferred green sensitizers plus a thioether sensitizer are processed in a sulfonamido-pphenylenediamine color developer. Alternatively part or all of the thioether can be in layers other than the greensensitive layer or can be in the color developer provided the thioether is present in the element during color development.

The oxacarbocyanine dyes utilized in my invention include these represented by the formula:

R2 (X )ul wherein G and G each represents a group, such as, a halogen atom (e.g., chloride, bromide, iodine, fluorine), the hydroxyl group, an alkoxy group (e.g., methoxy, ethoxy, propoxy, butoxy, etc.), an amino group (e.g., amino, methylamino, dimethylamino, diethylamino, etc.), an acylamido group (e.g., acetamido, propionamido, butyramido, etc.), an acyloxy group (e.g., acetoxy, propionoxy, etc.), a carbalkoxy group (e.g., carbethoxy, carbopropoxy, carbobutoxy, etc.), an alkoxycarbonylamino, group (e.g., ethoxycarbonylamino propoxycarbonylamino, butoxycarbonylamino, etc.), and a phenyl group (e.g., phenyl, tolyl, etc.) such that not more than one of G and G represents a phenyl group; G and G each represents the same or a different group, e.g., the hydrogen atom, a halogen atom (e.g., chlorine, bromine, fluorine and iodine); R and R each represents the same or a different alkyl group (e.g., methyl, ethyl, sulfoethyl, carboxyethyl, propyl, butyl, sulfobutyl, carboxybutyl, etc.); Z represents the hydrogen atom, an alkyl group (e.g., methyl, ethyl, propyl, etc.), or an aryl group (e.g., phenyl, tolyl, etc.); X represents an acid anion (e.g., chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate, ethyl sulfate, perchlorate, p-toluenesulfonate, etc.); and n represents an integer of from 1 to 2, such that n represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group.

The benzimidazolocarbocyanine dyes used to advantage in my invention include those having the formula:

wherein W and Y each represents the same or difierent group, such as, the hydrogen atom, a halogen atom (e.g., chlorine, bromine, iodine, fluorine), an alkoxy group (methoxy, ethoxy, butoxy, etc.), an amino group (e.g., amino, methylamino, dimethylamino, diethylamino, etc.), an acylamido group (e.g., acetamido, propionamido, butyramido, etc.), an acyloxy group (e.g., acetoxy, propionoxy, etc.), an alkoxycarbonylamino group (e.g., ethoxycarbonylamino, propoxycarboxylamino, etc.); W and Y each represents the same or different group, such as, the hydrogen atom, and a halogen atom (e.g., chlorine, bromine, iodine, and fluorine); R and R each represents the same or a different alkyl group, such as, methyl, ethyl, propyl, butyl, etc.; R and R each represents the same or a different alkyl group (e.g., methyl, ethylsulfoethyl, carboxypropyl, butyl, sulfobutyl, etc.); X represents an acid anion (e.g., chloride, bromide, iodide, thiocyana'te, sulfamate, methyl sulfate, ethyl sulfate, perchlorate, p-toluenesulfonate, etc.); and m represents an integer of from 1 to 2, such that m represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group.

Typical examples illustrating the dyes of Formula I include those in which the substituents of the said formula are defined by the following table.

G G, G2 G; R; R Z X6 5-(31 H suliopropyL. sultopropyl" ethyl none. 5-pheuy1 H suliobutyl sulfopropyL- ethyl none. 5-phenyl. H sulfobutyl sulfopropyL. ethyl none.

sulfobutyl... sulfobutyl ethyl none. su1i0propyl. suliopropyL ethy1 none.

ethyl ethyl ethyl iodide. 7 fi-acetamldo- H S-acetamido. H methyl methyl ethyl iodide. 8 fi-acetamide- H 5-acetamldo. H ethyl ethyl ethyL... iodide. 9 5acetoxy H 5-aeet0xy H ethyl ethyl.-. methyl. perchlorate. 10 5-carb- H 5-earb- H ethyl ethyl H iodide ethoxy. ethoxy. 11 5-hydroxy.-- H 5-hydroxy H ethyl ethyl ethyl percthlora e. 12 5-methoxy H 5-methoxy H sulfopropyL- sulfopropyl ethyl none.

Typical examples illustrating the dyes of Formula II and the substituents of the said formula are defined by the following table.

The synthesis of the compounds of Formulas III through VI are well known in the art, e.g., US. Patents 3,021,215, 3,192,046, etc.

Ru X19 R3 R4 R5 ethyl ethyL..- eth H H yl ethylI..- ethyl E"... 5'acetamido H 5-aeetamido- H methyL. methyl methyL F aeetoxy H 5-acetoxy H ethyl ethyl. hyl. G"... 5-Cl 6-01 5-01 fi-Cl ethyL. ethyL. ethyl yl sulfobutyl none. ethyl ethyl. suliobutyl sultobutyl none. eglhlylfln theyl ethyl sullobutylm" none. e

wherein R is an aliphatic radical having from 2 to 20 carbon atoms and e represents a positive integer of at least 2, the depicted sulfur atom being attached to a carbon atom of R said carbon atom having directly attached thereto the hydrogen atom. The terminal groups of such polymers are generally hydrogen atoms, halogen atoms, alkenyl groups (e.g., vinyl, allyl, etc.), carboxylic groups (e.g. carboxyl, carboxylic amide, carboxylic ester, such as carbomethoxyl, carbethoxyl, etc.), hydroxyl groups (or salts thereof, e.g., sodium, potassium, etc.), or combinations of these.

The linear polymers represented by Formula III above, comprise a well-known class of polymeric materials. Typical of the polymers embraced by Formula III are those polymers represented by the following formula:

wherein R R R and R each represents a hydrocarbon alkylene group containing from about 2 to 20 carbon atoms (e.g., ethylene, trimethylene, 1,2-propylene, tetrabutylene, pentamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, etc.), L and L each represents an oxygen atom, a sulfur atom, an amino group (substituted or not) such as amino, methylamino, ethylamino, etc., carbamyl (-NHCO), carbonylamido (CONH-), carbonyl, oxycarbonyloxy, oxycarbonyl (OOC), carbonyloxy (-COO), etc., provided that L does not represent an oxycarbonyl group when L represents a carbonyloxy group and L does not represent a carbamyl group when L represents a carbonylamido group, and p and 7 each represents a positive integer of from 1 to 5, and g represents the values given above, i.e., a positive integer of at least 2. An especially useful group of polymers represented by Formula IV comprises the polymers represented by the following formula:

wherein a, b, c, and d each represents a positive integer of from 2 to 20 and g, f, and p each have the values given above.

Another group of polymers embraced by Formula III are represented by the Formula: (VI) H0R (SR S-R OH wherein R and R are as defined previously and h is an integer of from 1 to 3.

Typical thioether sensitizers useful in my invention are: (1) Poly-2-2-thiodiethyl succinate [IO-(f CH2 GH2E-O-CH2 CH2S CH2 CH2] (2) 1,17-di[N-ethyl carbamyl] 6,12 dithia-9-oxaheptadecane [C2H5NH C CH2) 5-S CH2)2-]2O (3 6,l2-dithia-1,17-heptadecanediol HO( CH S-( CH S-(CH ,-,OH (4) 3,6-dithia-l,8-octanediol (5) Pentamethylene bis[(2-hydroxyethyl)-methylsulfonium p-toluenesulfonate] (6) Poly[thiodiethylene glutarate] CO(CH2)2S(CH2)2OC(CHz) [ll 1.

(7) Poly(glycol-3,3-thiodipropionate) (14) Poly(allyl ethyl mercapto acetate) L (1120 CO 0112802115] 7 Poly ether-ester-sulfide) According to my invention, I incorporate in a gelatin silver halide emulsion a thioether sensitizer with one or more of the. oxacarbocyanine dyes of Formula I described previously with one or more of the benzimidazolocarbocyanine dyes of Formula II described previously. However, my sensitizing combinations can be employed in photographic silver halide emulsions in which the carrier or vehicle is a hydrophilic colloid other than gelatin or utilized with gelatin, such as, for example, albumin, agaragar, gum arabic, alginic acid, etc., or a hydrophilic resin such as polyvinyl alcohol, polyvinyl pyrrolidone, a cellulose ether, a partially hydrolyzed cellulose acetate, an alkyl a-crylate-acrylic acid resin, etc., which has no deleterious effect upon the light-sensitive silver halide. The dyes of Formula I and Formula II can be employed in the combinations of the invention in various concentrations depending upon the particular emulsion, concentration of the silver halide, particular results desired, etc. The optimum concentration of a sensitizing dye can be determined in a manner well known to those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a different concentration of the sensitizing dye. The optimum concentration of my sensitizing combinations can, of course, be readily determined in the same manner, by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing different concentrations of the. individual components in the combination. In determining the optimum concentration for the spectral supersensitizing combination, it is advantageous to employ, at first, concentrations of the individual dyes less than their optimum concentrations. The concentrations of the individual dyes can then be increased until the optimum concentration of the supersensitizing combination is determined.

The methods of incorporating sensitizing dyes in silver halide emulsions are well known to those skilled in the art and these known techniques are employed in dispersing the dyes of my invention in the emulsions. These sensitizing dyes can be directly dispersed in the emulsions, or they can first be dissolved in some convenient solvent, such as pyridine, methyl alcohol, acetone, etc. (or mixtures of such solvents), or diluted with Water in some instances, and added to the emulsions in the form of these solutions. If desired, the dyes can be separately dissolved in an appropriate solvent and added separately to the emulsion, or they can be dissolved in the same or different solvent and these solutions mixed together before addition is made to the silver halide emulsions. The dyes can be dispersed in the finished emulsions and should be uniformly distributed throughout the emulsions before the emulsions are coated on a suitable support, such as, paper, glass, cellulose ester film, polyvinyl resin film (e.g., polystyrene film, polyvinyl chloride film, etc.) polyester film, etc. The following procedure has been found quite satisfactory: Stock solutions of the dye (or dyes) of Formula I and dye (or dyes) of Formula II are prepared by separately dissolving these dyes in appropriate solvents as described above. Then, to the fiowable silver halide emulsion the desired amount of stock solution of one of the dyes is slowly added while stirring the emulsion. Stirring is continued until the dye is thoroughly incorporated in the emulsion. Then, the desired amount of stock solution of the other dye is slowly added to the emulsion while stirring. Stirring is continued until the second dye is thoroughly incorporated in the emulsion. The thioether sensitizer may be added to the emulsion before or after the addition of the dyes. The sensitized emulsions can then be coated on a suitable support and the coating allowed to dry. In some instances, it may be desirable to heat the emulsion for a few minutes before coating onto the suitable support. The details of such coating techniques are well known to those skilled in the art. The foregoing procedure and proportions are to be regarded only as illustrative. Clearly, my invention is directed to any silver halide emulsion containing a combination of the afor said dyes with a thioether sensitizer whereby a supersensitizing effect is obtained.

In most cases, it is convenient to add the sensitizing dyes to the emulsions before the coupler dispersion is added.

The color-formers (couplers) are incorporated in the emulsions in the customary manner, e.g., by adding a dispersion of the coupler in a water-insoluable but Waterpermeable material to the emulsion, or by adding a dispersion of the alkali metal salt of the coupler in water. When employing a dispersion of couplers in the aforesaid crystalloidal materials, the coupler (color former) which has been mixed with the high-boiling organic crystalloidal material to produce an oil-like mixture can be dispersed in water or gelatin solution or in any aqueous binder of colloidal character which is miscible with the silver halide emulsion. The dispersion can be effected with the aid of a homogenizer, colloid mill or the like, and the dispersions can be stabilized by the addition of emulsifying agents such as those of the well-known higher fatty alcohol sulfate type. The dispersion may also be formed by dispersing a solution of coupler and crystalloidal material in a solvent of low boiling point such as butyl acetate with water or gelatin solution and subsequently removing the low-boiling solvent by evaporation. Here also an emulsifying agent can be used. The mixture of coupler and crystalloidal material may be dissolved in a solvent of low boiling point such as butyl acetate with water or gelatin solution and subsequently the low-boiling solvent is removed by evaporation. Here also an emulsifying agent can be used. It is important that the mixture of coupler and crystalloidal material be a liquid at ordinary temperatures so that liquid particles are formed When the mixture of coupler and crystalloidal material is emulsified in water and mixed with the emulsion, the particles retaining the coupler in solution, yet being readily penetrated by the photographic developing solution and other processing baths. The nature and propotrions of the coupler and the crystalloidal material should be chosen so that the particles are liquid under the conditions of coating and processing the emulsion. With the aforesaid crystalloidal materials, there is little or no tendency to crystallization even when the coupler is present in a proportion amounting to 50% or more of the high-boiling crystalloidal material. The crystalloidal materials should also be substantially colorless and stable toward light, heat and moisture, in addition to being inert to the various processing baths which may be encountered, such as developers, oxidized developers, silver removal baths and fixing baths. They should have a sufficiently low refractive index so that solutions of the couplers in them have approximately the same refractive index as gelatin, thereby minimizing the opacity or light scattering of the coating. Most couplers themselves have high refractive indices and for this reason it is desirable that the oil formers have low refractive indices. The crystalloidal materials should be easily dis persible in the emulsions and should be chemically inert toward the couplers and dyes formed therefrom.

My invention is directed primarily to the ordinarily employed gelatino silver halide developing-out emulsions in which the silver halide can be silver chloride, silver chlorobromide, silver chlorobromoiodide, silver iodochloride, silver bromide and silver bromiodide. These ordinarily employed silver halide developing-out emulsions are emulsions which form surface latent image (see British Patent 581,772, accepted Oct. 24, 1946). However, silver halide emulsions which form latent image mostly inside the silver halide grains (see British Patent 581,772 supra) can also be employed in practicing my invention.

The coupler compounds used in the emulsion layers sensitized according to my invention are any of the wellknown compounds which combine with the oxidation product of primary aromatic amino silver halide color developing agents to form dyes, for example, the cyanforming phenolic couplers of US. Patents 2,266,452; 2,362,598; 2,589,004; 2,474,293; 2,521,908; 2,423,730; the magenta-forming pyrazolone couplers of US. Patents 1,969,479; 2,369,489; 2,600,788; 2,618,641; 2,511,231 and the yellow-forming open-chain reactive methylene couplers of US. Patents 2,298,443; 2,652,329; 2,407,210; 2,875,057 and 2,271,238. Likewise, the emulsions may contain colored color-forming couplers as described in US. Patents 2,521,908; 2,706,684; 2,455,169; 2,694,703; 2,455,170; 2,453,661; 3,034,892; and 2,983,608.

The emulsions can be chemically sensitized by any of the accepted procedures. The emulsions can be digested with naturally active gelatin, or sulfur compounds can be added such as those described in Sheppard US. Patents 1,574,944 and 1,623,499, and Sheppard and Brigham US. Patent 2,410,689.

The emulsions can also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium and platinum, all of which belong to Group VIII of the Periodic Table of elements and have an atomic weight greater than 100. Rrepresentative compounds are ammonium chloropalladate, potassium chloroplatinate and sodium chloropalladite, which are used for sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli US. Patent 2,448,060, and as antifoggants in higher amounts as described in Trivelli and Smith US. Patents 2,566,245 and 2,566,263.

The emulsions can also be chemically sensitized with gold salts as described in Waller and Dodd US. Patent 2,399,083 or stabilized with gold salts as described in Damschroder US. Patent 2,597,856 and Yutzy and Leermakers US. Patent 2,597,915. Suitable compounds are potassium chloroaurite, potassium aurithiocyanate, potassium chloroaurate, auric trichloride and 2-aurosulfobenzothiazole methochloride.

Any undesirable fog in the sensitized emulsions of my invention can be suppressed and reduced to normal levels by using various compounds such as the mercury compounds of Allen, Byers and Murray US. Patent 2,728,663; Carroll and Murray US. Patent 2,728,664; Leubner and Murray U.S. Patent 2,728,665; the ballasted hydroquinones of Thirtle et a1. U.S. Patent 2,701,197; the sulfurcontaining stabilizers of Herz and Kalenda US. Patents 3,043,696 and 3,057,725; the disulfide stabilizers of Herz US. application Ser. No. 421,994, filed Dec. 29, 1964. Combinations of these couplers, sensitizers, stabilizers, etc. can be utilized if desired.

Any of the well known primary aromatic amino colorforming silver halide developing agents such as the pphenylenediamines (e.g., diethyl-p-phenylenediamine, dimethyl-p-phenylenediamien, 2 amino-5-diethylaminotoluene, monomethyl-p-phenylenediamine, 2 amino 5- (n-ethyl-N-laurylamino)toluene, N ethyl-N-(fi-methanesulfonamidoethyl) 4 aminoaniline, 4 [N ethyl N- (6 hydroxyethyl)amino]aniline, etc.), the p-aminophenols and their substittution products where the amino group is unsubstituted can be used to advantage in the color development of my color elements. Particularly, efiicacious results are obtained with color developing agents of the dialkyl ubstituted-p-phenylenediamine type, the alkyl groups preferably being lower alkyl groups having 1 to 4 carbon atoms. There is a cooperating eifect between the above-described dialkyl substituted-p-phenylenediamine developing agents, thioether chemical sensitizers and green spectral sensitizing dyes.

The aqueous alkaline color developer solution used to advantage contain, in addition to the color developing agent, any of the usual components, e.g., alkali metal carbonates, sulfites, iodides, bromides, phosphates, etc.,

and can contain all or a part of the thioether compound.

The following specific examples will serve to still further illustrate my invention.

EXAMPLE 1 Single layer coatings of the incorporated coupler type which varied only in the green sensitizers therein were prepared. In these coatings a sulfur and gold sensitized gelatino silver bromoiodide emulsion containing a dispersion of a magenta color forming pyrazolone coupler of the type described in Fierke et al. US. Patent 2,801,171, issued July 30, 1957, was coated on a film support. Two coatings were made in which the indicated sensitizers were used. Two samples of each coating were exposed in an intensity scale sensitometer with one sample processed, as indicated below, in the Eastman Color Negative (ECN) film process and the other processed in the Eastman Color Print (ECP) process. These processes diifer in that the color developing agent in the ECN process is 4 amino-3-methyl-N-ethyl-B-(methane sulfonarnido)-ethylaniline sesquisulfate hydrate, Color Developing Agent I, whereas the color developing agent in the ECP process is 4-amino-3-methyl-N,N-diethylaniline hy drochloride, Color Developing Agent II. Coating A, outside my invention, was green sensitized by the incorporation therein of the following combination of dyes:

Dye I 3-carboxymethyl 1 ethylthia 2' cyanine iodide (.0875 g./silver mole).

Dye II 9-ethyl 3,3 di({3 methoxyethyl 5,5 diphenyl)- oxacarbocyanine iodide (.0875 g./silver mole).

Dye III Anhydro 5,5 dichloro 9 ethyl 3,3 di(3-sulfopropyl)-oxacarbocyanine hydroxide, sodium salt (.300 g./ silver mole), and

Dye V Anhydro 5,5,6,6 -tetrachloro 1,1,3 triethyl-3-(3- sulfobutyl)-benzimidazocarbocyanine hydroxide (.120 g./ silver mole).

and containing, in addition, 0.1 g. of 1.17-di[N-ethylcarbonyl]-6,l2-dithia 9 oxaheptadecane per silver mole. When exposed and processed as described above, the following results were obtained.

E CN process (contains Color Developing Agent I), relative green speed ECP process (contains Color Developing Agent II) relative green speed The results show a very substantial increase in relative green speed for my coating B over coating A of the prior art when developed with Color Developing Agent I. However, when Color Developing Agent II was used my coating had more than 100% higher relative green speed than the prior art coating.

EXAMPLE 2 Two coatings were made in the manner described in Example 1: Coating C outside the invention, was similar to Coating B but contained no 1,17-di[N-ethylcarbamy1]- 6,12-dithia-9-oxaheptadecane or other thioethers.

E ON process, E OF process,

relative relative green speed green speed Coating:

The results show even large relative green speed increases for my coatings and again demonstrates the synergistic increase produced when a dialkyl-p-phenylenediamine color developing agent is used in the color development step.

EXAMPLE 3 Seven additional coatings (E through K) were prepared in the manner described in Example 1:

Coating E, outside my invention used as control, was similar to Coating C of Example 2.

Coating F was the control +0.25 g. of poly[thiodiethylene glutarate] per silver mole.

Coating G was the control +0.5 g. of poly [thiodiethylene glutarate] per silver mole.

Coating H was the control +0.75 g. of poly[thiodiethylene glutarate] per silver mole.

Coating I was the control +0.12 g. of l,l7di-[N-ethylcarbamyl]-6,l2-dithia-9-oxaheptadecane per silver mole.

Coating I was the control +0.25 g. of 1,17-di-[N- ethylcarbamyl]-6,l2-dithia-9-0xaheptadecane per silver mole.

Coating K was the control +0.12 g. of 6,12-dithia-l, 17-heptadecane diol per silver mole.

Two samples of each of these coatings were exposed and processed as described in Example 1 to yield the following speed data:

EXAMPLE 4 The following basic multilayer color elements structure was utilized in this example.

Layer 6.Gelatin layer.

Layer 5.Blue-sensitive gelatino silver halide emulsion layer containing an open-chain coupler compound of the type described in US. Patent 2,875,057 containing a reactive methylene group for formation of a yellow image.

Layer 4.-Carey-Lea silver yellow filter layer.

Layer 3.Green sensitive gelatino silver halide emulsion layer containing a pyrazolone magenta-forming coupler of the type described in U.S. Patent 2,600,788.

Layer 2.--Gelatin interlayer.

Layer 1.Red sensitive gelatino silver halide emulsion layer containing a phenolic cyan-forming coupler of the type described in US. Patent 2,423,730.

12 SUPPORT Eight multilayer color elements (A through H) were coated with the indicated variations from the basic element described above.

Element A (control for Elements B, C and D) contained the following combination of Dyes I, II and II in Layer 3:

Dye: G./silver mole I .263 II .263

III .131

Element B was the same as Element A, but in addition to Dyes I, H and III contained 0.5 g./silver mole of the linear thioether compound poly[thiodiethylene glutarate];

in Layer 3.

Element C was the same as Element B but had 0.5 g./silver mole of poly[thiodiethylene glutarate] in Layer 1.

Element D was the same as Element C but had 0.5 g./ silver mole of poly[thiodiethylene glutarate] in Layer 5.

Element E (control for Elements F, G and H) contained the following combination of Dyes IV and V in Layer 3:

Dye IV--.450 g./silver mole Dye V.l g./silver mole Element F was the same as Element E but in addition to Dyes IV and V contained 0.5 g./silver mole of poly[thiodiethylene glutarate] in Layer 3.

Element G was the same as Element F but contained 0.5 g./silver mole of poly[thiodiethylene glutarate] in Layer 1.

Element H was the same as Element G but contained 0.5 g./silver mole of poly[thiodiethylene glutarate] in Layer 5.

Elements F to H are elenmts of my invention, Elements A to E represent elements of the prior art and are included for comparative purposes.

All of the above elements were then exposed and processed in the ECN Process to yield the following data:

TABLE 1 Relative speed R G B Element:

A (control for B, C and D) 100 100 100 B 110 91 105 110 80 102 110 126 100 100 94 132 105 107 135 110 97 132 132 is used. The following data were obtained by processing Elements A through H in the ECP Process.

Table II shows that when the thioether sensitized Elements, B, C and D that are outside my invention are processed according to my invention with a dialkylsubstituted-p-phenylenediamine color developing agent, the green-speed is increased by more than 100%. This is unexpected from the results shown in Table I for these same elements.

Table II shows the apparent synergistic green speed increase of from 289 to 336% produced in my Elements F, G and H when they are processed with a dialkyl-substituted p-phenylene-diamine color developing agent. Similar results are obtained when other dialkyl-substituted pphenylene diamine color developing agents are used in place of Color Developing Agent I. As stated before, similar results are obtained by incorporating all or part of the thioether compound in one or more layers of the element continguous to the green-sensitive layer or incorporating all or part of the thioether compound in the color developer solution.

My invention provides valuable methods for increasing the green speed in green-sensitized photographic silver halide emulsion layers which have been sensitized with thioether compounds by using a preferred combination of sensitizing dyes and color developing with any of the color developing agents or where the preferred combination of sensitizing dyes is not user, color developing with a dialkyl-substituted-p-phenylenediamine color developing agent. Substantial and unexpected increases in green speed are obtained by using my color element-color process system. Synergistic increases in green speed of up to 336% are obtained by color developing my preferred color elements with a dialkyl-substituted-p-phenylcne diamine color developing agent.

The invention has been described in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. A light-sensitive photographic silver halide emulsion containing:

( 1) an oxacarbocyanine dye having the formula:

wherein G and G each represent a group selected from the class consisting of a halogen atom, the hydroxyl group, an alkoxy group, an amino group, an acylamido group, an acyloxy group, a carbalkoxy group, an alkoxycarbamylamino group, and a phenyl group, such that not more than one of G and G represents a phenyl group; G and G each represent a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; Z

represents a group selected from the class consisting of the hydrogen atom, an alkyl group and an aryl group; X represents an acid anion; n represents an integer of from 1 to 2, such that n represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group;

(2) a benzimidazolocarbocyanine dye having the formula:

wherein W and Y each represents a group selected from the class consisting of the hydrogen atom, a halogen atom, an alkoxy group, an amino group, an acylamido group, an acyloxy group, and an alkoxycarbonylamino group; W and Y each represents a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; R and R each represents a group selected from the class consisting of an alkyl group, a sulfoalkyl group and a carboxyalkyl group; X represents an acid anion; and m represents an integer of from 1 to 2, such that m represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group; and

(3) a silver halide thioether sensitizer having the formula:

wherein R is an aliphatic radical having from 2 to 20 carbon atoms, and 2 represents a positive integer of at least 2, the depicted sulfur atom being attached to a carbon atom of said R radical, said carbon atom having directly attached thereto the hydrogen atom.

2. In a light-sensitive photographic silver halide emulsion containing a color-forming coupler the improvement comprising the incorporation in said emulsion of:

(1) at least one oxacarbocyanine dye having the forwherein G and G each represent a group selected from the class consisting of a halogen atom, the hydroxyl group, an alkoxy group, an amino group, an acylamido group, an acyloxy group, a carbalkoxy group, an alkoxycarbamylarnino group, and a phenyl group, such that not more than one of G and G represents a phenyl group; G and G each represent a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; Z represents a group selected from the class consisting of the hydrogen atom, an alkyl group and an aryl group; X represents an acid anion; n represents an integer of from 1 to 2, such that n represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group;

115 (2) at least one benzimidazolocarbocyanine dye having the formula:

wherein W and Y each represents a group selected from the class consisting of the hydrogen atom, a halogen atom, an alkoxy group, an amino group, an acylamido group, an acyloxy group, and an alkoxycarbonylamino group; W and Y each represents a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; R and R each represents a group selected from the class consisting of an alkyl group, a sulfoalkyl group and a carboxyalkyl group X represents an acid anion; and m represents an integer of from 1 to 2, such that m represents an integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group;

(3) A sensitizing amount of a thioether having the formula R7S e wherein R is an aliphatic radical having from 2 to 20 carbon atoms, and e represents a positive integer of at least 2, the depicted sulfur atom being attached to a carbon atom of said R radical, said carbon atom having directly attached thereto the hydrogen atom.

3. A light-sensitive photographic emulsion of claim 2 in which the thioether has the formula:

wherein R represents a hydrocarbon alkylene group containing from about 2 to 20 carbon atoms; R represents a hydrocarbon alkylene group containing from about 2 to 20 carbon atoms; R represents a hydrocarbon alkylcne group containing from about 2 to carbon atoms; R represents a hydrocarbon alkylene group containing from about 2 to 20 carbon atoms; L and L each represents a member selected from the class consisting of oxygen, sulfur, the amino group, an alkylamino group, the carbamyl group, the carbonylamido group, the carbonyl group, the oxycarbonyloxy group, the oxycarbonyl group, the carbonyloxy group, such that L does not represent an oxycarbonyl group when L represents the carbonyloXy group, and L does not represent the carbamyl group when L represents the carbonylamido group; p and 7 each represents a positive integer of from 1 to 5 and g represents a positive integer of at least 2.

4. A light-sensitive photographic emulsion of claim 2 in which the thioether has the formula:

wherein R represents a hydrocarbon alkylene group containing from about 2 to 20 carbon atoms; R represents a hydrocarbon alkylene group containing from about 2 to 20 carbon atoms; and It represents an integer of from 1 to 3.

5. A light-sensitive photographic emulsion of claim 2 in which the thioether is 1,l7-di[N-etl1ylcarbamyl]-6,12 dithia-9-oxaheptadacane.

6. A light-sensitive photographic emulsion of claim 2 in which the thioether is poly[thiodiethylene glutarate].

7. A light-sensitive photographic emulsion of claim 2 in which the thioether is 6,l2-dithia-l,l7-heptadecanediol.

8. A light-sensitive photographic emulsion of claim 2 in which the oxacarbocyanine dye is anhydro-5,5'-dichloro 9 ethyl-3,3-di(3-sulfopropyl)-oxacarbocyanine hydroxide, sodium salt, and the benzimidazolocarbocyanine dye is anhydro 5,5,6,6-tetrachloro-l,l',3-triethyl-3- (3-sulfobutyl)-benzimidazolocarbocyanine hydroxide.

9. In a multicolor, multilayer light-sensitive element for color photography containing a green-sensitized silver halide emulsion layer having incorporated therein a magenta-forming coupler, the improvement comprising the addition to said emulsion of:

(1) an oxacarbocyanine dye having the formula.

wherein G and G each represent a group selected from the class consisting of a halogen atom, the hydroXyl group, an alkoxy group, an amino group an acylamido group, an acyloxy group, a carbalkoxy group, an alkoxycarbonyl amino group, and a phenyl group, such that not more than one of G and G represents a phenyl group; G and G each represent a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; Z represents a group selected from the class consisting of the hydrogen atom, an alkyl group and an aryl group; X represents an acid anion; n represents an integer of from 1 to 2, such that n represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group;

(2) a benzimidazolocarbocyanine dye having the forwherein W and Y each represents a group selected from the class consisting of the hydrogen atom, a halogen atom, an alkoxy group, an amino group, an acylamido group, an acyloxy group, and an alkoXycar-bonylamino group; W and Y each represents a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; R and R each represents a group selected from the class consisting of an alkyl group, a sulfoalkyl group and a carboxyalkyl group; X represents an acid anion; and m represents an integer of from 1 to 2, such that m represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group; and theaddition to at least one layer of said element,

(3) a sensitizing amount of a thioether having the formula:

wherein R is an aliphatic radical having from 2 to 20 carbon atoms, and e represents a positive integer of at least 2, the depicted sulfur atom being attached to a carbon atom of said R radical, said carbon atom having directly attached thereto the hydrogen atom.

10. A process for color photography comprising the step of contacting an image exposed multilayer, multicolor photographic silver halide element having as the green-sensitive layer a silver halide emulsion containing:

( 1) at least one oxcarbocyanine dye having the formula:

represents a group selected from the class consisting of an alkyl group, a sulfoalkyl group and a carboxyalkyl group; X represents an acid anion; and m represents an integer of from 1 to 2, such that m represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group; with an aqueous alkaline color developer containing a p-phenylene-diamine color developing agent in the presence of a thioether sensitizer for silver halide having the formula:

wherein R is an aliphatic radical having from 2 to carbon atoms, and e represents a positive integer of at least 2, the depicted sulfur atom being attached to a carbon atom of said R radical, said carbon atom having directly attached thereto the hydrogen atom.

alkyl group; R represents an alkyl group; Z represents a group selected from the class consisting of 20 the hydrogen atom, an alkyl group and an aryl group; X represents an acid anion; n represents an integer of from 1 to 2, such that n represents the integer 1 when at least one of R and R represents a group selected from the class consisting of a sulfoalkyl group and a carboxyalkyl group;

(2) at least one benzimidazolocai'bocyanine dye having the formula:

11. The process of claim 10 for color photography in which the oxacarbocyanine dye is anhydro-5,5'-dichloro- 9-ethyl-3,3-di(3-sulfopropyl) -oxacarbocyanine hydroxide, sodium salt.

12. The process of claim 10 for color photography in which the color developing agent is a dialkyl substituted p-phenylene diamine.

References Cited UNITED STATES PATENTS R9 R4 1 r 3,397,060 8/1968 Schwan et al. 96104 2,266,;61 1/192: Heseltlilne etlal. 96-482 2, 88, 45 9/19 Carro et a 961 W i Y 2,945,763 7/1960 Jones 96 104 N/ \N 3,046,135 7/1962 Beavers 96107 W1 1 Y1 3,046,129 7/1962 Graham et al 96-107 t u r 3,369,902 2/1968 Abbott 96-106 wherein W and Y each represents a group selected from the class consisting of the hydrogen atom, a halogen atom, an alkoxy group, an amino group, an acylamido group, an acyloxy group, and an alkoxycarbonylamino group; W and Y each represents a group selected from the class consisting of the hydrogen atom and a halogen atom; R represents an alkyl group; R represents an alkyl group; R and R each NORMAN G. TORCHIN, Primary Examiner M. F. KELLY, Assistant Examiner US. Cl. X.R. 96124 gg gy UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,506,144} Dated April 11;, 1970 Inventor-(3) Robert F. Motter It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Eolumn 6, line 14.6, delete the second "S" in that part of the formula which reads "-S-S(CH -S" so that this part of the formula will read ----S-(GH S Column 12, line 6, between "and" and "in", delete "II" and substitute in its place ---III--.

Column 114., line 19, at the end of the formula, add the figure "1 so that the corrected formula will, at the end, read Column 15, line 23, between "represents" and "inte er", delete "an" and substitute in its place ---the---; line 3 in that part of the formula reading "R )-L change the parenthesis marks to read. ---R1OCL1-.,

MGNED ANb QEALED acre-191) t Attest:

EdmrdMHelcher,Ir'.

0 mun I. JR. A teatmg ffioer commissioner of Patents 

